End brush



Nov. 21, 1961 R. w. DOLAN 3,009,184

END BRUSH v Original Filed Jan. 29, 1958 INVENTOR. 0866 W. DOM/V United States Patent 3,009,184 END BRUSH Robert W. Dolan, Baltimore, Md., assignor to Pittsburgh Plate Glass Company, Allegheny County, Pa., a corporation of Pennsylvania Original application Jan. 29, 1958, Ser. No. 711,845. Divided and this application Nov. 9, 1960, Ser. No.

2 Claims. (Cl. -180) This invention relates to power-driven brushes and it has particular relation to power-driven brushes of the so-called endor cup-brush type in which double-length bristles or fill are provided to extend approximately coaxially of the brush.

It has heretofore been disclosed to form so-called end brushes by securing double-ended or folded fill material in a cup like element Which is provided with a central stem projecting coaxially from the bottom thereof and being adapted to be secured in a chuck upon a driven mandrel.

Such brushes are Well adapted for brushing or buffing of surfaces having cavities and depressions which are difficult of access by conventional power-driven brushes of the disc or wheel-type.

In the fabrication of the end brushes, fully satisfactory modes of securing the fill material in the cups and especially those of smaller sizes have not heretofore been obtained. Obviously, a satisfactory end brush should be inexpensive to produce, simple of construction and should be rugged and adapted to withstand long usage without loss of the fill material. Also, the fil-l material should be well and uniformly compacted into a tight bunch. Also, there should be no axial voids, that might leave too many filaments Without support by neighboring filaments.

One of the more common prior art constructions in the end or cup brush field is illustrated in Benyak Patent, 2,449,158. In this construction, the till material extends coaxially through a substantially cylindrical ring and is then doubled back about the outside of the ring to form a tuft which is held in cup. A disadvantage of this construction resides in the fact that it is difiicult adequately to compress the fill material within the ring because of the incompressibility of the ring itself. Furthermore, the fabrication of such construction is comparatively complicated, because it requires preliminary threading of a bunch of fill through the ring and bending back of the bunch about the outside of the ring before the brush knot is inserted in the cup.

In accordance with the provisions of the present invention in its preferred form, an end brush is provided in which the doubled, untwisted fill material comprising a bundle of parallel, untvvisted fibers is secured in place within a cup by means of a bar-like pin disposed in the loops or bights of the fil-l material and extending across the cup, and being provided with an angular stem extending through a hole in the bottom of the cup, said stem being adapted to be secured in a chuck upon an arbor or mandrel to provide a direct drive through the stem between the chuck and the fill material in the cup.

In the drawings wherein like numerals refer to like parts, FIGURE 1 is a view partly in section and partly in elevation of a brush structure embodying the invention.

FIGURE 2 is a sectional view illustrating a stage in the formation of a brush by the procedure of this invention.

The brush shown in the drawings comprises a cup 38 which has a cylindrical side Wall 39 and :a bottom 40 with a central opening 40a for the stem or shank element of the brush, hereinafter to be described. The securing "ice element for the fill material comprises a cross-pin 41 which is spaced from the bottom of the cup and is disposed in the bight or loop portion of the bunch or tuft T of untwisted fill material 42 projecting beyond the edges of the cup. The rear portions of the fill contiguous the loop are held from radial outward flaring by the wall 39. The pin is further provided with a stem 43 at its midpoint, said stem projecting through the opening 40a in the bottom of the cup and providing a stem or shank for driving the brush. Said stem or shank is illustrated as being secured in a conventional chuck C upon a mandrel or spindle M. The stem provides .a direct drive for the tuft to rotate the same about its longitudinal axis without torque upon the cup.

In the assembly of this brush, two bunches of loose fill material are provided, one upon each side of the stem or shank 43. The bunches are laid across the cup and the mid-portions thereof are forced downwardly, as by plunger P as indicated in FIGURE 2, so that they are doubled about the pin to provide a unitary tuft T. After the midpor-tion of the fill material has been forced into the cup, the upper edge of the latter may be crimped inwardly, as at 44, to compact the tuft by an appropriate operation, such as spinning or pressing. Subsequently, the ends of the fill material in the tuft are trimmed to appropriate outline. Finally, the stem 43 is secured from displacement from the opening 40a in the bottom of the cup as by spot Welding or by a stake, as at 45, or if preferred, the stem may be screw-threaded to receive a nut (not shown). Any of these modes of fastening are quite adequate because, as already pointed out, when the stem or shank 43 is secured in a chuck C upon mandrel M, the stem directly and positively drives the cross-pin 41 and the latter in turn directly and positively drives the bunch or tuft of fill material. It will thus be apparent that the cup or any part thereof does not act as a means to transfer torque load to the tuft. The possibility of slippage of the tuft in the cup is thus obviated re ga-rdless of the type of means adopted for securing the stem or shank 43 from displacement from the hole or opening 40a. This is important when the brush is subjected to heavy Work loads since slippage in the cup under such conditions could result in a high degree of wear and development of frictional heat with resultant rapid deterioration of the brush.

The forms of the invention as herein described are by way of illustration. It will be apparent to those skilled in the art that numerous modifications may be made therein without departure from the spirits of the invention or the scope of the appended claims. This application is a division of copending application, Serial No. 711,845, filed January 29, 1958.

I claim:

1. An end type brush comprising a substantially cylindrical cup having a bottom with an axially formed perfora tion, a transverse holding pin disposed in the cup in spaced relationship to the bottom thereof and having a stem portion projecting through the hole, said stern providing means for securing the brush in a chuck on a driving mandrel, and untwisted fill material divided into two bunches, each of the bunches being untwisted and being doubled about the pin, a bunch upon each side of the stem, said bunches being compacted by and held by the side walls of the cup into a single tuft, and projecting outwardly from the edges of the cup, the stem and pin directly driving the tuft.

2. An end type brush comprising a substantially cylindrical c-up having a bottom with an axially formed perforation, a transverse holding pin disposed in the cup in spaced relationship to the bottom thereof and having a stem portion projecting through the hole, said stem providing means for securing the brush in a chuck on a driving mandrel, and fill material divided into two bunches, each of the bunches being untwisted and being doubled about the pin, a bunch upon each side of the stem, said bunches being compacted \by the walls of the cup into a single tuft .and projecting outwardly from the edges of the cup, the edges of the cup being inwardly erimped to press the fill material into a compact bundle, the tuft being directly rotated by the pin and stem.

References Cited in the file of this patent UNITED STATES PATENTS Rodgers Jan. 17, 1928 Fogliasso Jan. 15, 1946 Peterson May 9, 1961 FOREIGN PATENTS Great Britain Jan. 2, 1936 

